SPEED AND TORQUE VARIATIONS OF MOTOR

Electric Motor

The work of themotoris to conversion of the electrical energy, supplied by the controller, and to mechanical energy to move the load.There are mainly two types ofmotors, AC and DC.The basic principle for both themotorsis same.There are two magnets that are to run amotorthe permanent magnet and the electro magnet because these are helpful in producing the force which is required to run amotor.InElectro magnets the magnetic field produced is stronger than in the permanent magnets.There are somemotoris a type of brushless electricmotorin which when anACsupply fed to the windings of thestator, it creates a magnetic field that induce a current in the windings of therotor. Rotation of therotorresults interaction of the magnetic field created by the current ofrotorwith the field of thestator.

Speed and Torque Variations of Motor

Thetorqueand thetorquedensity of theelectric motoris not dependent only on itsspeed. It is a function of thefluxand the armature current.

Effects of Flux

Increase in thefluxdecreases thespeedbut it increases thetorque. Iftorqueis decreased with the same as there is a decreasing the field current:

The back EMF drops instantly, and thespeedremaining constant because of the inertia of heavy armature.

TORQUE/SPEED CURVES

In order for effectively design of theD.C. motors, it is necessary to understand their characteristic curves. For every motor, there is a specificTorque/Speedcurve and Power curve.

The graph above shows atorque/speedcurve of a typicalD.C. motor. Note that torque is inversely proportional to the speed of the output shaft. In other words, there is tradeoffs’ between how much torque a motor delivers, and how fast the output shaft spins.Motorcharacteristics are frequently given as two points on this graph:

The stall torque,, represents the point on the graph at which the torque is a maximum, but the shaft is not rotating.

The no load speed,, is the maximum output speed of the motor (when no torque is applied to the output shaft).

Ouremail-based homework helpassistance offers brilliant insights and simulations which help make the subject practical and pertinent.

Transtutors.comprovides timely homework help and assignment help at reasonable charges with detailed answers to yourElectrical Engineeringquestions so that you get to understand your assignments or homework better apart from having the answers. Our tutors are remarkably qualified and have years of experience providingMotorhomework help or assignment help.